Kanellos J, Pietersz G A, McKenzie I F
J Natl Cancer Inst. 1985 Aug;75(2):319-32.
Methotrexate (MTX) was covalently bound to two different murine monoclonal antibodies, one reactive with human colon carcinoma and the other reactive with the transferrin receptor. The drug-antibody complexes were examined for their in vitro and in vivo potency against tumors. The conditions of coupling were closely monitored, with particular attention being paid to the preservation of both drug and antibody activity. After activation of MTX with N-hydroxysuccinimide, MTX was bound to the antibodies under conditions leading to maximum protein and antibody recovery. Although the coupling conditions for both antibodies were different, up to 13 molecules of MTX-antibody molecule could be attached with retention of antibody activity. Such conjugates were active in vitro and could inhibit the growth [( 3H]deoxyuridine uptake) of cells in culture. The conjugates were highly specific, having no effect on tumors lacking the antigen; however, MTX complexed to antibody was less potent than the free drug. In vivo, the MTX-antibody impaired the growth of established tumors. Thus MTX-antibody complexes can be successfully produced and can be used for the immunotherapy of tumors.
甲氨蝶呤（MTX）与两种不同的鼠单克隆抗体共价结合，一种对人结肠癌有反应，另一种对转铁蛋白受体有反应。检测了药物 - 抗体复合物对肿瘤的体外和体内效能。对偶联条件进行了密切监测，特别注意药物和抗体活性的保持。在用N - 羟基琥珀酰亚胺激活MTX后，在能实现最大蛋白质和抗体回收率的条件下将MTX与抗体结合。尽管两种抗体的偶联条件不同，但每个抗体分子最多可连接13个MTX分子且抗体活性得以保留。此类缀合物在体外具有活性，可抑制培养细胞的生长[（3H）脱氧尿苷摄取]。这些缀合物具有高度特异性，对缺乏相应抗原的肿瘤无作用；然而，与抗体结合的MTX比游离药物的效力低。在体内，MTX - 抗体复合物抑制了已形成肿瘤的生长。因此，MTX - 抗体复合物能够成功制备并可用于肿瘤的免疫治疗。
